Apparatus for transporting horizontally split boxless sand casting molds for foundry purposes

ABSTRACT

In an apparatus for the transportation of horizontally split, boxless sand casting molds (1) for foundry purposes, from a molding station via a casting station to the knocking-out point by means of a series of transport plates (5, 50) which are guided one against the other along a track and whose length in each case, in the direction of transport, is equal to or only slightly larger than the corresponding length of the casting mold placed on top in each case, each transport plate (5, 50) has, at least at one of its ends, preferably the end facing away from the molding station, a face strip (6) arranged substantially vertical to it and directed upward, which prevents an offset between transport plate and casting mold.

This application is a continuation of U.S. application Ser. No. 015,028,filed Feb. 2, 1987, now abandoned.

The invention relates to an apparatus for the transportation ofhorizontally split, boxless sand casting molds for foundry purposes froma molding station via a casting station to the knocking-out point bymeans of a series of transport plates which are guided one against theother along a track and whose length in each case, in the direction oftransport, is equal to or only a little larger than the correspondinglength of the casting mold placed on it in each case, and against whicha drive engages.

An apparatus of this type is known (German Auslegeschrift No.2,417,197), in which the supporting surfaces of the transport plates forthe casting molds are not only of flat design, but also unlimited on allsides in such a way that, in the event of possible jolts, ie. suddenaccelerations or decelerations, the casting molds on the transportplates can shift on the transport plates. Such an offset may impair notonly the casting mold concerned itself, but also the neighboring castingmold against which it collides. Furthermore, a cast mold has thetendency to swell, ie. it expands under the effect of the casting, andcan thus likewise impair adjoining casting molds, in particular thosewhich have not yet been cast, since these themselves do not swell andcan therefore easily be dented. Finally, problems may also arise intransferring the casting molds from one transport line to anothertransport line by once again an offset occurring or mold sand crumblingfrom the faces of a casting mold.

With respect to the problem of the swelling of a casting in a boxlesscasting mold, it should be mentioned that although attempts are made toavoid casting parts having different casting weights in one and the sameseries of successive sand casting molds, since in this case the swellingbehavior likewise tends to be different according to the differentcasting weights, in such a way that a sand casting mold cast with alarger casting weight of course swells more, this cannot of coursealways be avoided.

The object underlying the invention is seen as creating an apparatus ofthe type specified at the start, in which no offset of the sand castingmolds with respect to the transport plates can occur any longer and aswelling of the sand casting molds after casting cannot result in thepossibility of neighboring sand casting molds, whether already cast orstill empty, being touched or even impaired or damaged.

This object is achieved in the case of an apparatus of the typementioned in that each transport plate has at least at one to its ends aface strip arranged substantially vertical to it and directed upward.

This face strip delimits the position of each new sand casting moldbrought onto a transport plate from a molding station in the moldingmachine with respect to the preceding sand casting mold, namely by theface strip being arranged between the two molds. Sudden accelerations ordecelerations can thus not lead to displacements or an offset of thesand casting molds on the associated transport plates. If it is desired,furthermore, to prevent particularly reliably that for instance theupper half of the sand casing mold, thus the half above the mold partingor separating line, is displaced or offset with respect to the lowerhalf of the sand casting mold, it is advantageous to design the facestrip as a face wall which has a height covering the parting line of thesand casting mold. The height of this face wall can be appropriatelyequal to the height of the sand casting mold. In any case, a touching ofsuccessive or neighboring sand casting molds owing to the swellingprocess of cast molds is prevented since, according to the invention, aface strip or face wall is always arranged between two successive sandcasting molds. In this arrangement, the face strip is preferablyarranged at the end of the transport plate facing away from the moldingstation in such a way that the respective sand casting molds deliveredby the molding machine can be simply pushed in the direction oftransport onto the transport plate.

Since it is desirable to prevent any swelling of cast sand casting moldsat all, at least in the direction of transport, the drive appropriatelyengages at the end of the series of transport plates facing the moldingstation, while to achieve a compressive stress in the transport platesbraking forces are applied at the other end, which are greater than anycasting mold swelling forces but of course are less than the driveforces. This furthermore ensures that the drive forces are constantlytransmitted via the transport plates.

If face strips are arranged at both ends of a transport plate, brakingforces may be dispensed with because the swelling forces which arepossibly exerted by a sand casting mold after its casting are absorbedby the two face strips and thus the platform alone. In the case of thisembodiment, the pushing-on of a sand casting mold may be carried outfrom one side, perpendicular to the direction of transport. In order toprevent a lateral offset of the sand casting mold on its transport plateduring pushing-on, an additional face strip or face wall may be providedas a stop along one side of the transport plate, of course along thatside which is opposite the side from which pushing is performed.

Each face wall may be provided advantageously with grooves for gasremoval, at least on the side facing its platform, and this furtherreduces the swelling tendency of the cast sand casting molds. It goeswithout saying that these grooves are continuous, ie. designed to beopen on both sides and, furthermore, are appropriately arrangedvertically and/or horizontally and at a distance from one another, sothat, if applicable, a network of gas-removing grooves extends over therespective faces of each face wall facing the sand casting molds. Ifthere is merely one face wall provided at one of the ends of a platform,said face wall shall be provided with gas removal grooves on both sides,since it adjoins two sand casting molds.

The invention and its advantageous developments are explained in moredetail below with reference to exemplary embodiments shown in thedrawing, in which:

FIG. 1 shows a first embodiment with a series of transport plates, inside view;

FIG. 2 shows a section along the line II--II in FIG. 1;

FIG. 3 shows a second embodiment;

FIG. 4 shows a section along the line IV--IV in FIG. 3.

FIG. 1 shows an apparatus for the transportation of sand casting molds 1for foundry purposes, to be precise for the transportation of boxlesssand casting molds 1 split horizontally into two halves 2 and 3.Transport takes place from a transport station (not shown) in arrowdirection A via a casting station (likewise not shown) to theknocking-out point (not shown) by means of a series of transport plates5 which are guided one against the other along a track 4 and whoselength L in each case, in the direction of transport A, is equal to oronly slightly larger than the corresponding length L of the casting mold1 placed on it in each case. Furthermore, a drive (not shown) engageswith the series of transport plates.

Each transport plate 5 has at its end facing away from the moldingstation (not shown) a face strip 6 arranged substantially vertical to itand directed upward. The drive forces are indicated by the arrow B. Thisdrive B appropriately engages at the end of the series of transportplates 5 facing the molding station; furthermore, to achieve acompressive stress in the transport plates 5, braking forces accordingto arrow C are applied at the other end of the series of transportplates 5 and are greater than any casting mold swelling forces, butsmaller than the drive forces B. This ensures that the transport plates5 are constantly in contact one against the other, possibly in the wayshown with the face strips 6 interposed between them. It is understoodhowever that the face strips can equally well be placed on the transportplates 5 in such a way that their length available for the sand castingmolds 1 is shortened by the thickness d of the face plates 6.

In the preferred embodiment shown, the face strip 6 is designed as aface wall which has a height H covering the parting line 7 of therespective sand casting mold 1. In the case of the sand casting molds 1,in the embodiment shown, this height H corresponds to the height of thesand casting molds. However, a particular advantage of the presentinvention is that sand casting molds having a different height anddifferent casting weights can also be used in one and the same series oftransport plates or one and the same mold line, as the sand castingmolds 1' show. The swelling forces occurring in a sand casting mold 1'after casting according to arrows D are of course greater than in thecase of the lower sand casting molds 1 having parts with smaller castingweights. Nevertheless, owing to the face strips 6 or face walls arrangedbetween them, this does not result in impairment of the preceding orfollowing sand casting molds 1 and 1', respectively. Furthermore, thetransport plates 5 also remain in contact with one another, providedthat the braking forces C are greater than the swelling forces D, butsmaller than the drive forces B.

As emerges particularly clearly from FIG. 2, the face strips 6 or facewalls are provided on both sides with continuous grooves 8 for gasremoval. These grooves may be arranged, in a way not shown, not onlyvertically but also horizontally, in the latter case a network (notshown) of grooves being produced which are in each case arranged at adistance from one another.

Advantageously, in the case of the apparatus according to the inventionit is insignificant whether on some occasions a transport plate remainsunoccupied as is the case with the transport plates 5 shown in FIG. 1 inthe center and at the end. The respective adjoining sand casting molds 1and 1' are nevertheless supported on either side by face strips 6 orface walls. This support ensures during a transfer of the sand castingmolds with the transport plates from one track to the other that nothingcan crumble, at least at one face, namely the face up against a facestrip 6 or face wall and, moreover, also that no displacement betweenthe mold halves 2 and 3 on the one hand and the transport plate 5 on theother hand can take place in this operation.

In the second embodiment represented in Figures 3 and 4, face strips orface walls 60, 60' are arranged at both ends of a transport plate 50.This makes it possible to dispense with braking forces since, even inthe case of a broken chain of transport, ie. with a distance between twotransport plates 50, the sand casting molds 1, 1' concerned cannot swellsince they cannot swell between the face walls 60, 60'. Furthermore, inthe embodiment shown, an empty transport plate 50a is shown as anexample, an additional stop strip 60" being provided along one of itssides such that the sand casting mold concerned can be pushed up fromthe side until in contact with this additional stop strip 60", so thatsaid casting mold, surrounded on three sides, precisely assumes itsposition on the transport plate 50a. It goes without saying that thisstop strip 60" as well, like all face strips 6, 60, 60', may be designedas a wall. The expression "from the side" means of course in FIG. 3"perpendicular to the plane of the drawing" . FIG. 4 shows a face wallwith gas removal grooves 8 provided merely on one side, in each casefacing the platform. The other side does not of course require anygrooves in this embodiment of the apparatus.

Moreover, the same reference symbols have been used in this embodimentas in the embodiment according to FIGS. 1 and 2.

Even if the text above constantly refers to transport plates 5, whichmay be transported for example on trains of rollers or the like, itshould nevertheless be pointed out that in the embodiments shown thetransport plates 5 have been developed further, by wheels indicated at9, into transport cars which run on a surface 10 forming the track. Itgoes without saying that the invention is not restricted to the use ofsuch cars.

I claim:
 1. Apparatus for the transportation of horizontally split,boxless sand casting molds for foundry purposes from a molding stationvia a casting station to the knocking-out point by means of a series ofhorizontal mold underlay plates which are guided one against the otheralong a track and whose length in each case, in the direction oftransport, is equal to or only a little larger than the correspondinglength of the casting mold placed on it in each case, and against whicha drive engages, characterized in that each mold underlay plate has atleast at one of its ends a substantially vertical face strip rigidlyattached thereto and extending upwardly for directly engaging throughouta major portion of its height a boxless sand casting mold resting on theunderlay plate to prevent displacement of the casting mold both aboveand below the horizontal split; and said face strip having in each casea height covering the horizontal split of the sand casting mold. 2.Apparatus according to claim 1, characterized in that the face strip isarranged at the end of the mold underlay plate facing away from themolding station.
 3. Apparatus according to claim 1 or 2, characterizedin that the drive engages at the end of the series of mold underlayplates facing the molding station.
 4. Apparatus according to claim 2,characterized by brake means for imposing a braking force at the otherend of the series of underlay plates from the drive greater than anycasting mold swelling forces.
 5. Apparatus according to claim 1,characterized in that face strips are arranged at both ends of a moldunderlay plate.
 6. Apparatus according to claim 1, characterized in thata stop strip is provided along one side of teach mold underlay plate andrigidly attached thereto and extending upwardly therefrom beyond thehorizontal split of the sand casting mold.
 7. Apparatus according toclaim 1, characterized in that each face strip is provided withcontinuous grooves for gas removal, at least on the side facing its moldunderlay plate.
 8. Apparatus according to claim 7, characterized in thatthe grooves are arranged vertically and/or horizontally and at adistance from one another.